BANGKOK, Sept 13 (Reuters) - Thailand's largest olefins
maker, PTT Chemical Pcl , will acquire a stake in a
U.S. bioplastic polylactic acid (PLA) maker as part of a foreign
expansion drive, a source at Thailand's Energy Ministry said on
Tuesday.

"They are in talks with the seller and therefore the portion
(of the stake) cannot be disclosed," the source, who declined to
be identified, told Reuters. "That being said, the deal is close
to being finalised this month," he said, adding that the seller
plans to build a new U.S. bio-plastic plant.

PTT Chemical has capacity for 2.88 million tonnes of olefins
products a year and is in the process of merging with another
PTT affiliate, PTT Aromatics and Refining Pcl ,
expected to be competed in October.

Once completed, it would create Southeast Asia's
second-biggest petrochemicals firm by market value after
Malaysia's Petronas Chemical and the merged firm will
be named PTT Global Chemical Pcl.

At 0809 GMT, PTT Chemical shares were down 0.8 percent,
while the broader market was 0.6 percent lower.